Ultra‐High Pressure Phosphor Based on an Eco‐Friendly Perovskite Via Isovalent and Heterovalent Co‐Doping Engineering

Abstract Tin halide perovskites are good eco‐friendly alternatives to lead halide perovskites, whose toxicity problem can effectively be eliminated. In order to improve the fluorescence properties, in this work, a novel non‐toxic perovskite phosphor is successfully synthesized, employing both isovalent and heterovalent co‐doping chemical engineering. The photoluminescence of this new phosphor is prominent in the visible light regime, and the corresponding color can readily be tuned from green to red. Based on DFT calculations and time‐resolved photoluminescence spectra, a physical model that accounts for the light emission is proposed, where efficient energy transfers between self‐trapped excitons are addressed. Interestingly, the physical effect of Sb 3 + heterovalent doping on the phosphor is observed in transient absorption spectra, manifesting itself as a spectral broadening. Remarkably, with increasing the pressure on the phosphor from 1 atm up to an ultra‐high value of 23.5 GPa, an interesting evolution of the photoluminescence spectrum is clearly revealed. This new phosphor and the dual‐ion co‐doping strategy may advance sustainable material science.